This invention relates to telephonic voice message systems, sometimes referred to as voice mail systems, and, in particular, to methods of controlling and authenticating transmission of telephonic voice message data in interconnected networks of such systems.
Electronic communication may be conducted employing a variety of formats including direct telephonic voice communication, facsimile document communication, electronic mail communication, and telephonic voice message communication. Facsimile document communication and electronic mail communication may be characterized as document-based and the other two formats as voice-based.
Direct telephonic voice communication is unique among these formats in that it requires simultaneous participation by all parties. In many business situations, the requirement for simultaneous participation is unnecessary, disruptive, time-consuming, and often impossible because a called party telephone is busy or the party is otherwise unavailable. As a consequence, nonsimultaneous communication formats, such as facsimile document communication, electronic mail communication, and telephonic voice message communication are becoming preferred over direct telephonic voice communication for many situations.
Because ever-increasing volumes of information are being transmitted by the different nonsimultaneous communication formats, document store and forward systems have been developed to improve the efficiency, cost-effectiveness, and useability of facsimile document and electronic mail communications formats. Document store and forward systems implement features such as delivering a single communication to multiple parties, deferring communication delivery to a reduced rate time period, deferring a communication delivery until business hours in a different country or time zone, forwarding a communication to a predetermined address, returning a communication delivery notification, identifying and/or authenticating a particular communication, and delivering a particular communication according to a delivery priority.
Document-based store and forward systems, such as one described in U.S. Pat. No. 5,014,300 for METHOD AND APPARATUS FOR ACCESSING A FACSIMILE STORE AND FORWARD NETWORK, have been developed for compatibility because facsimile machines and electronic mail systems are based on digital communication technology that is intended for transmitting messages among widely separated locations, often across international boundaries. The communication receiving facsimile machines and computers are manufactured by a variety of manufacturers according to internationally accepted features, standards, and communication protocols that were developed to satisfy a common need.
In contrast, voice-based store and forward systems have not necessarily been developed for compatibility because prior voice mail systems were primarily intended for transmitting analog messages among users sharing a common voice message system, such as one installed in a corporation. Therefore, voice mail systems have been manufactured by a variety of manufacturers, each adopting a proprietary set of features and communication protocols that were developed to satisfy the needs of each manufacturer.
Clearly, voice-based store and forward systems would benefit from many of the features and capabilities of document-based store and forward systems. However, the incompatible protocols employed by different voice message systems hinder the development of all such capabilities. Moreover, because of the distances and complexities of telecommunications networks, voice messages transmitted in such networks are subject to transmission delays and costs that render impractical features such as voice signature authentication of a destination voice message address.
For example, virtually all voice message systems return to an originator a recipient""s voice signature to prevent inadvertently sending a voice message to an incorrect recipient. The voice signature is typically the recorded name of the recipient user spoken in the user""s voice, for example, xe2x80x9cJohn Smith.xe2x80x9d In prior non-networked voice message systems, the name, voice signature, and other information associated with every user is recorded in a xe2x80x9cuser file.xe2x80x9d When an originator enters a recipient voice message address, the voice message system accesses the user file and returns the associated voice signature to the voice message originator to authenticate the entered voice message address.
Unfortunately, in a networked voice message system, when an originator enters a recipient voice message address that is at a remote destination, the originating voice message system cannot readily access the destination user file without encountering undue telecommunications-related delay and expense. The destination user file is rendered completely inaccessible if the voice message is marked for deferred delivery or for grouped transmission with other voice messages. Moreover, local duplication, updating, and storage of the myriad of destination user voice signatures is impractical. For example, the Octel VMX-5000 networked voice message system stores duplicate user files in each system and updates all of them in response to user changes. Such duplication requires a heavy and ongoing database maintenance commitment. To circumvent the database maintenance problem, the ATandT Intuity voice message system employs a centralized user file database facility. However, this approach requires time consuming network wide intercommunications, which unacceptably delays returned voice signatures.
What is needed, therefore, is a communication method suitable for intercommunicating among and rendering compatible the features and authentication methods of multiple disparate voice-based message systems and voice message store and forward units distributed across a geographically distributed telecommunications network.
An object of this invention is to provide a method by which message originators can authenticate the destination addresses of telephonic voice messages transmitted through a complex telecommunications network.
Another object of this invention is to provide a method by which a destination voice message system can authenticate the originator of a questionable voice message.
A voice message store and forward service includes a geographically distributed network of voice message store and forward units (xe2x80x9cVMSFUsxe2x80x9d) that intercommunicate by employing a protocol A that transfers voice messages between VMSFUs with user information transfer units that include the voice message and a message envelope containing enhanced feature information, and service information transfer units that include notifications of successful and/or unsuccessful transfer of a user message. An originating VMSFU accepts a voice message from a voice message system, delivers the voice message to a destination VMSFU, and/or returns a delivered or not delivered notification to the voice message system. The destination VMSFU delivers the voice message to a voice message system identified by a destination voice message address indicated in a voice message header. Protocol A conveys enhanced features, such as conveying any unique features of disparate voice message systems, converting between message formats or voice encoding algorithms, translating addresses, mapping message recipient addresses, and accommodating message priorities. VMSFUs attach to each voice message a globally unique message identification number for tracing message progress, reporting on message delivery status, and providing accounting information. The store and forward service provides services, such as delivering voice messages at a specified time, redirecting voice messages to alternate VMSFUs, deferring delivery of specified voice messages, delivering voice messages in accordance with specified priority and delivery commitments, and minimizing message delivery costs with a scheduler.
In an embodiment of this invention, authentication of a network recipient voice message address employs generating and locally storing at an originating voice message system a xe2x80x9cnetwork filexe2x80x9d that includes xe2x80x9cvoice clipsxe2x80x9d and associated voice message addresses that are extracted from voice messages received across the network from other voice message systems. A voice clip is extracted from the first one to three seconds of the received voice message, and typically contains a greeting identifying both the recipient and the originator, for example, xe2x80x9cHello John this is Marsha.xe2x80x9d Over time, the network file will grow to contain many voice clips and associated network voice message addresses, which are substituted for a network recipient""s remotely stored voice signature.
For example, when a voice message originator, such as John, enters Marsha""s network voice message address, the originating voice message system searches the network file for the Marsha""s voice message address, retrieves Marshals associated voice clip, xe2x80x9cHello John this is Marsha,xe2x80x9d and substitutes it for the inaccessible voice signature. If Marsha""s voice message address is not found (this will always be the case until a first voice message is received from Marsha), the originating system responds with the entered voice message address and indicates that an associated voice clip is not found in the network file. To prevent the network file from growing excessively large, thereby causing excessive processing time and storage costs, the voice message system periodically purges the network file of all but active and recently received voice clips.
In another embodiment of this invention, voice authentication of a voice message originator entails encoding selected voice clips and their associated network voice message addresses into a xe2x80x9cvoice print file.xe2x80x9d When a voice message is subsequently received from a voice message originator, the voice message system extracts a new voice clip, generates a new voice print, and compares it with the originally stored voice print associated with the voice message address. If the voice prints are substantially the same, the received voice message is annotated with a xe2x80x9cauthenticationxe2x80x9d message indicating that the voice message was recorded by a positively identified originator. However, if the voice prints are substantially different, the received voice message is annotated with a xe2x80x9cwarningxe2x80x9d message indicating that the voice message may have been recorded by an imposter.
Additional objects and advantages of this invention will be apparent from the following detailed description of a preferred embodiment thereof, which proceeds with reference to the accompanying drawings.